diff options
Diffstat (limited to 'kernel/include/linux/sysctl.h')
| -rw-r--r-- | kernel/include/linux/sysctl.h | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/kernel/include/linux/sysctl.h b/kernel/include/linux/sysctl.h new file mode 100644 index 000000000..fa7bc2992 --- /dev/null +++ b/kernel/include/linux/sysctl.h @@ -0,0 +1,221 @@ +/* + * sysctl.h: General linux system control interface + * + * Begun 24 March 1995, Stephen Tweedie + * + **************************************************************** + **************************************************************** + ** + ** WARNING: + ** The values in this file are exported to user space via + ** the sysctl() binary interface. Do *NOT* change the + ** numbering of any existing values here, and do not change + ** any numbers within any one set of values. If you have to + ** redefine an existing interface, use a new number for it. + ** The kernel will then return -ENOTDIR to any application using + ** the old binary interface. + ** + **************************************************************** + **************************************************************** + */ +#ifndef _LINUX_SYSCTL_H +#define _LINUX_SYSCTL_H + +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/wait.h> +#include <linux/rbtree.h> +#include <uapi/linux/sysctl.h> + +/* For the /proc/sys support */ +struct ctl_table; +struct nsproxy; +struct ctl_table_root; +struct ctl_table_header; +struct ctl_dir; + +typedef int proc_handler (struct ctl_table *ctl, int write, + void __user *buffer, size_t *lenp, loff_t *ppos); + +extern int proc_dostring(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_dointvec(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_dointvec_minmax(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_dointvec_jiffies(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_dointvec_ms_jiffies(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_doulongvec_minmax(struct ctl_table *, int, + void __user *, size_t *, loff_t *); +extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, + void __user *, size_t *, loff_t *); +extern int proc_do_large_bitmap(struct ctl_table *, int, + void __user *, size_t *, loff_t *); + +/* + * Register a set of sysctl names by calling register_sysctl_table + * with an initialised array of struct ctl_table's. An entry with + * NULL procname terminates the table. table->de will be + * set up by the registration and need not be initialised in advance. + * + * sysctl names can be mirrored automatically under /proc/sys. The + * procname supplied controls /proc naming. + * + * The table's mode will be honoured both for sys_sysctl(2) and + * proc-fs access. + * + * Leaf nodes in the sysctl tree will be represented by a single file + * under /proc; non-leaf nodes will be represented by directories. A + * null procname disables /proc mirroring at this node. + * + * sysctl(2) can automatically manage read and write requests through + * the sysctl table. The data and maxlen fields of the ctl_table + * struct enable minimal validation of the values being written to be + * performed, and the mode field allows minimal authentication. + * + * There must be a proc_handler routine for any terminal nodes + * mirrored under /proc/sys (non-terminals are handled by a built-in + * directory handler). Several default handlers are available to + * cover common cases. + */ + +/* Support for userspace poll() to watch for changes */ +struct ctl_table_poll { + atomic_t event; + wait_queue_head_t wait; +}; + +static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) +{ + return (void *)(unsigned long)atomic_read(&poll->event); +} + +#define __CTL_TABLE_POLL_INITIALIZER(name) { \ + .event = ATOMIC_INIT(0), \ + .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } + +#define DEFINE_CTL_TABLE_POLL(name) \ + struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) + +/* A sysctl table is an array of struct ctl_table: */ +struct ctl_table +{ + const char *procname; /* Text ID for /proc/sys, or zero */ + void *data; + int maxlen; + umode_t mode; + struct ctl_table *child; /* Deprecated */ + proc_handler *proc_handler; /* Callback for text formatting */ + struct ctl_table_poll *poll; + void *extra1; + void *extra2; +}; + +struct ctl_node { + struct rb_node node; + struct ctl_table_header *header; +}; + +/* struct ctl_table_header is used to maintain dynamic lists of + struct ctl_table trees. */ +struct ctl_table_header +{ + union { + struct { + struct ctl_table *ctl_table; + int used; + int count; + int nreg; + }; + struct rcu_head rcu; + }; + struct completion *unregistering; + struct ctl_table *ctl_table_arg; + struct ctl_table_root *root; + struct ctl_table_set *set; + struct ctl_dir *parent; + struct ctl_node *node; +}; + +struct ctl_dir { + /* Header must be at the start of ctl_dir */ + struct ctl_table_header header; + struct rb_root root; +}; + +struct ctl_table_set { + int (*is_seen)(struct ctl_table_set *); + struct ctl_dir dir; +}; + +struct ctl_table_root { + struct ctl_table_set default_set; + struct ctl_table_set *(*lookup)(struct ctl_table_root *root, + struct nsproxy *namespaces); + int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); +}; + +/* struct ctl_path describes where in the hierarchy a table is added */ +struct ctl_path { + const char *procname; +}; + +#ifdef CONFIG_SYSCTL + +void proc_sys_poll_notify(struct ctl_table_poll *poll); + +extern void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_root *root, + int (*is_seen)(struct ctl_table_set *)); +extern void retire_sysctl_set(struct ctl_table_set *set); + +void register_sysctl_root(struct ctl_table_root *root); +struct ctl_table_header *__register_sysctl_table( + struct ctl_table_set *set, + const char *path, struct ctl_table *table); +struct ctl_table_header *__register_sysctl_paths( + struct ctl_table_set *set, + const struct ctl_path *path, struct ctl_table *table); +struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); +struct ctl_table_header *register_sysctl_table(struct ctl_table * table); +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table); + +void unregister_sysctl_table(struct ctl_table_header * table); + +extern int sysctl_init(void); + +extern struct ctl_table sysctl_mount_point[]; + +#else /* CONFIG_SYSCTL */ +static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table) +{ + return NULL; +} + +static inline struct ctl_table_header *register_sysctl_paths( + const struct ctl_path *path, struct ctl_table *table) +{ + return NULL; +} + +static inline void unregister_sysctl_table(struct ctl_table_header * table) +{ +} + +static inline void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_root *root, + int (*is_seen)(struct ctl_table_set *)) +{ +} + +#endif /* CONFIG_SYSCTL */ + +int sysctl_max_threads(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos); + +#endif /* _LINUX_SYSCTL_H */ |